Liquid pump



June 16, 1942. is. G. PARSONS LIQUID rum Filed Feb. 28, 1941 a 2Sheets-Sheet l INVENTOR.

is 6', fir/190 5 BY 94 guw ATTORNEY.

June 1942. B. G. PARSONS 2,286,302

LIQUID PUMP Filed Feb. 28,. 1941 .2 Sheets-Sheet 2 INVENTOR. 5 6,/Z;/-s0/25 ATTORNEY Patented June 16, 1942 LIQUID PUMP Ben G. Parsons,Detroit, Mich., assignor to American Bosch Corporation, Springfield,Mass., a corporation of New York Application February 28, 1941, SerialNo. 381,068

14 Claims.

This invention relates to liquid pumps and particularly to those forpumping gasolene, fuel oil,

water and other liquids in metered amounts per,

stroke, preferably beginning at a variable time in the pump stroke andending at a fixedtime therein as is predetermined by an adjustment ofthe pump.

The primary object of the invention is to provide a small, compact andinexpensive pump of this kind of comparatively large capacity but lightin weight and rigid in construction. One of the preferred featurescontributing to these characteristics is a hollow delivery plungerhaving a shaped peripheral rim in the form of one or a plurality ofhelices whereby the plunger may be turned to an adjusted angularposition in its barrel in cooperation with one or'a plurality of inletports to predetermine the amount of liquid delivered per stroke througha delivery valve co,- axially arranged in the barrel, and whereby thereturn spring for the plunger may beat least partly housed therein insuch manner as to react against the delivery valve directly.

Another object is to provide a desirable form of indicator for theadjustable delivery mechanism of a pump of this or other kind.

Still another object is to provide in a single cylinder pump of this orother kind an improved stationary filter arrangement for the liquidsupthereof, whereby surplus liquid is returned from the barrel throughthe filter to assist in cleansing the filter.

The structural features and arrangements by which these and otherobjects and advantages are obtained will be understood from thefollowing description taken in connection with the ac companyingdrawings, which show, as an example, the preferred embodiment of asingle cylinder pump having a delivery valve and adapted in accordancewith the invention for pumping gasolene as for instance to the nozzle ofan internal combustion engine. Inthe drawings:

Fig. 1 is a central vertical section, partly in elevation, of the pumpwith the plunger in its lowermost position; Fig. 2 is a section on line2-2 of Fig. 1; Fig. 3 is a section on line 3-3 of Fig. 1 but with theplunger in its uppermost position; and Fig. 4 is a section on line 44 ofFig. 3.

The/exterior housing of the pump is formed by a filter housing I ofstainless steel and a pump housing plunger barrel 2 of a hard steelalloy synthetic rubber gasket 4. These two housings are held tightly onthe gaskets by the hollow nut 5 threaded into the pump housing andseated on a gasket 6 onthe top of the filter housing, which nut alsosecures in place the delivery duct I extending from the outlet port ofthe pump to a nozzle in the engine manifold or cylinder in the wellknown manner. The pump housing is fastened by the bolt fastenings 8 tothe cam shaft housing 9 ofduraluminum which is provided with 1 a base orflange mounting on the engine as detelescoped therein-for a portion ofits axial length sired. This shaft housing has two end covers i0fastened thereto by stud bolts ll, each cover having a ball bearing 12for the shaft I3, and one carrying an oil seal I4 while the other closesthe end of the shaft. The screw plugs l5 serve for filling andemptyingthe shaft housing with lubricant and the bolt fastenings 8tightly clamp in fixed position the quadrant l6 having two scales H andI8.

Arranged concentrically within the stationary filter housing I is afilter comprising an annular filter cage I!) of stainless steel, alsosecured between the gaskets 3 and 4, and an annular filter screen 20 ofany suitable kind as closely spaced bronze wires soldered to the cage atits upper and lower ends. ly arranged axial slots at 2| staggered in theupper and lower halves, and is readily exposed and The filter removedupon removing the housing I. housing has an inlet duct 22 and an outletduct 23 communicating with each other by means of the channel 24 aroundthe outside of the screen 20 so that, as gasolene is suppliedcontinuously through the inlet 22, the outside surface of the screen iswashed clear by the surplus gasolene of all adhering foreign particlesincluding lint. This clearing action is facilitated and increased by thepump inforcing back through the filter some of each charge. of gasoleneinitially sucked into the barrel on the downward stroke of the plunger.

Centrally within the pump housing 2 is a through axial bore at 25forming for the pump a cylindrical barrel in which reciprocates thedelivery plunger 26 of a hard steel alloy. The plunger is forcedupwardly in a sine wave characteristic movement by ring 21 mounted bymeans The cage has a plurality of circular- 4| with connecting portions.

mounted a return spring 32reacting between the crosswall 33 and theupper wall ofthe delivery valve 34, so as to return the plunger, aspermitted by the ring 21, from the uppermost position shown in Fig. 3 toits lowermost .position plunger are repeated so long as the shaft I3 isand thereby eliminates the need for the usual tappet cup or roller. Inthe uppermost part of the plunger barrel, the bore thereof is enlargedto provide a conicalseat at 35 for the delivery valve 34 and for athreaded portion for the nut 5. The head of the delivery valve is ofsmaller diameter than the upper bore and has in it a cross channel asshown, so that when the delivery valve is lifted off its seat thegasolene flows along the conical seat and around the head to thedelivery duct I. The delivery valve spring 38 reacts between the head 34and the upper interior cross wall of the nut 5, and is stronger than thespring 32 in all operative stressed'positions of the latter.

The pump housing 2 has diametrically opposite inlet ports 39 from theannular channel 40 just inside the filter housing, and the upperperipheral rim of the plunger 26 .is formed into twolongitudinally-extending oppositely-disposed helices These helices areso arranged with respect to the ports as to simultaneously cover andsimultaneously uncover the latter at definite points in thereciprocation of the plunger depending upon the angular position towhich the plunger is turned in the barrel. The adjusting mechanism forturning the plunger comprises an arm 42 loosely mounted for turning inan elongated slot at 43 in the pump housing (Fig. 4), and has a tongue44 fitted in the vertical slot at 3| of the plunger. Thus the arm 42 canturn the plunger to any angular position in the barrel within limitsdefined by the quadrant or the slot at 43, and the plunger can be movedup and down in any such predetermined angular position between thelowermost and uppermost points to which it is reciprocated. In theassembled pump, the arm 42 is held from coming out of the slot 3| by thearcuate part of the quadrant Hi.

The operation of the pump will now be de-' scribed. Starting with theplunger 26 in its lowermostposition, the delivery valve 34 is seated andthe inlet ports 39 are uncovered by the helices 4|, as shown in Fig. 1.At this time the space in the interior of the plunger and the barrel isfilled with gasolene from the previous downward suction stroke of theplunger. As the shaft I3 is turned by a shaft of the engine with whichit is associated, at cam shaft speed for a fourcycle engine and at crankshaft speed for a twocycle engine, the ring 21 forces the plungerupwardly. As soon as the ports 39 are covered by the plunger, thetrapped gasolene is compressed until the pressure thereon sufficientlyexceeds that effective to hold the delivery valve 34 closed. At thatpoint in the pump cycle, the delivery valve is forced off its seat andgasolene delivered through the duct 1 for the remaining part of theupward stroke of the plunger. At the beginning of the downward orsuction stroke of the plunger by the return spring 32, the deliveryvalve is closed by its spring 38 as a result of the decrease of pressureon the gasolene, and the pump barrel is filled with gasolene throughports 39. These alternating suction and delivery strokes of thedirections of flow to the outlet duct 23.

turned by the engine, and thus gasolene is delivered to the nozzle inthe manifold of the em gine or to the engine itself, or otherwise asdesired, in timed relation with the cycle of operation of the engine.

The instant in the pump cycle of the beginning of delivery of gasolene,and therefore the instant in the cycle of the engine to which the pumpis connected, is determined by the angular position of the plunger inits barrel because such position determines the.instant in which thehelices 4| cover the inlet ports 39 in the upward or delivery stroke ofthe plunger to exert pressure on the gasolene in the barrel. Since thedelivery of gasolene thereafter delivered continues until the end of thedelivery stroke of the plunger, which end point coincides with theuppermost position of the plunger, the amount of gasolene delivered perstroke is concomitantly predetermined. Thus the position of the arm 42indicates on scale H the angle through which delivery takes place, andat the same time indicates on scale I8 the percentage of the maximumamount of delivery of gasolene per stroke that occurs at that setting.Thus at the position shown in Fig; 2, the delivery extends for 60 out ofa possible and the volume of gasolene delivered per stroke is 50% of themaximum. It will be observed that the gasolene constantly flowingthrough inlet duct 22 is greater than the maximum ever delivered by thepump. The surplus passes around the annular channel 24 in both In sodoing the gasolene washes the outside surface of the filter screen 2|land thereby carries away with it any solid or other foreign particlesthat may have been filtered out of the gasolene that passed through thefilter screen. Since the screen extends completely around the pumpbarrel, the screen remains free of particles or other foreign matterthat may otherwise clog it. In this way, the pump is more reliable anddurable, and its metered accuracy of delivery is enhanced.

Also it will be observed that by making the plunger 26 hollow for aconsiderable portion of its axial length, which is practical for thepressure obtaining in the pump, its return spring 32 may be at leastpartly housed therein to thereby reduce the height and weight of thepump, and accordingly its strength and resistance to distortion inoperation. Furthermore, by arranging the helices 4| on the rim of theplunger, the means for controlling the beginning of injection and theamount of fiow per stroke, which may be minute, may be accurately,simply and inexpensively attained in a pump of this kind.

While I have disclosed the preferred embodiment only of a singlecylinder pump, it will be understood that many variations therein andmodifications thereof may be made within the broad terms of the appendedclaims. For instance, the features herein noted may be applied to amulticylinder. pump, and may be used in single or multicylinder form forpumping liquids other than gasolene. Also the filter may be arrangedoutside the pump, instead of being incorporated in it, and the adjustingand indicating mechanism may be of other form and operated eithermanually or by a governor controlled automatically by the engine.

It isto be understood that some of the novel features of the filterarrangement of this pump are covered in my application. Serial No.381,067, filed concurrently herewith.

Having thus described my invention, what I .claimis: P

'1. In a liquid pump having a plunger barrel with a coaxial outlet portand with an inlet port.

a delivery valve arranged in the outlet port, a

and delivery control and indicating mechanism ior turning said plungerin said barrel and tor indicating the position to which said plunger isdelivery valve, a spring extending into said plung- I er and reactingbetween it and said delivery .valve to effect the suction stroke or saidplunger and to draw liquid through the inlet port into said barrel, andcontrol means for controlling the amount oi liquid forced through saiddelivery valve in the delivery stroke of said plunger.

2. In a liquid pump having a plunger barrel with inlet and outlet ports,a delivery plunger which is reciprocative in said barrel and which hasat least a portion or its top surface longitudinally shaped iorcooperation with the inlet port, reciprocating means for reciprocatingsaid plunger to draw liquid through the inlet port into said barrelduring its suction stroke and to force liquid from said barrel throughthe outlet port during its delivery stroke, and delivery control meansfor turning said plunger in said barrel comprising a lever extendinginto a slot which is arranged in said plunger and is longitudinallyelongated so that said plunger may reciprocate.

' said barrel, a spring extending into the hollow portion of the plungerfor effecting its return stroke and to draw liquid through said inletport into said barrel, and a, lever which extends into said slot andwhich provides therein a longitudinal clearance to permit said plungerto be reciprocated. without reciprocating said lever.

4. In a liquid pump having a housing with a horizontally elongated slottherein and also having a plunger barrel with inlet and outlet ports, areciprocative delivery plunger in said barrel having an upper hollowportion with at least a portion of its rim longitudinally shaped forcooperation with the inlet port and also having a solid lower portionwith a longitudinally elongated slot therein, operating means for movingsaid plunger in its delivery stroke to force liquid through the outletport from said barrel, a spring extending into the hollow portion of theplunger for efiecting its return stroke and to draw liquid through saidinlet port into said barrel, and a lever which extends through said slotin the housing and into said slot in the plunger whereby said lever mayangularly turn said plunger at any point of reciprocation thereof insaid barrel to control a. delivery characteristic of said plunger.

5. In a liquid pump having a housing and also having a plunger barrelwith inlet and outlet ports, a delivery plunger which is reciprocativein said barrel and which has at least a portion of its top surfacelongitudinally shaped for cooperation with theinlet port, reciprocatingmeans for reciprocating said plunger to draw liquid through the inletport into said barrel during its suction stroke and to force liquid fromsaid barrel through the outlet port during its delivery stroke,

turned.

6. In a liquid pump having a housing with a horizontally elongated slottherein and also having a plunger barrel with inlet and outlet ports, areciprocative delivery plunger in said barrel having at least a portionof its top surface longitudinally shaped for cooperation with the inletport and also having a longitudinally elongated slot, reciprocatingmeans for reciprocating said plunger to draw liquid through the inletport into said barrel during its suction stroke and to force liquid fromsaid barrel through the outletport during its delivery stroke, anddelivery control and indicating mechanism comprising -a lever whichextends through said slot in the housing and into said slot in theplunger and also comprising an indicating quadrant fixed in said housingand'having an arcuate scale-divided portion which registers with saidlever in various positions to which the lever may be turned and whichacts to prevent said lever from being disengaged from said slots.

7. In a single cylinder liquid pump having a plunger housing with abarrel having an inlet the same.

8. In a single cylinder liquid pump having a plunger housing with abarrel having an inlet port, a delivery plunger reciprocative in saidbarrel, a filter housing which surrounds said barrel for at least a partof its length and which has inlet and outlet ports in communication witheach other and with the inlet port of said barrel,

- and a stationary filter screen which is'arranged in said filterhousing between the ports or said filter housing and the port of saidbarrel and which extends completely around said barrel, said .pumphaving means for returning surplus liquid from said barrel through saidfilter screen to assist in cleaning the same.

9. In a single cylinder liquid pump having a plunger housing with abarrel having oppositely disposed inlet ports, a delivery plungerreciprocative in said barrel, a' filter housing which surrounds saidbarrel for at least a part/of its length and which has inlet and outletports in communication with each other and with the inlet ports of saidbarrel, and a stationary filter screen arranged in said filterhousingbetween the ports of said filter housing and the ports of saidbarrel, said pump having means for returning surplus liquid from saidbarrel through said filter screen to assist in cleaning the same.

10. In a single cylinder liquid pump having a plunger housing with abarrel having oppositely disposed inlet ports, a delivery plungerreciprocative in said barrel, a filter housing which is fastened to saidplunger housing and around it for at least a .portion of its length andwhich has inlet and outlet ports in communication with each other, astationary perforated filter cage arranged between said plunger housingand filter housing, and a cylindrical filter screen covering theperforations therein, said pump having means for returning surplusliquid from said barrel through said filter screen to assist in cleaningthe same.

11. In a single cylinder liquid pump having a plunger housing which hasa barrel with oppositely disposed inlet .ports and which also has acircular channel around its outer periphery, a filter housing which isfastened to said plunger housing and around it for at least a portion ofits length and which has inlet and outlet ports in communication witheach other, a stationary cylindrical filter cage which is arrangedwithin said filter housing and which has a plurality of openings aroundits periphery, and a cylindrical filter screen mounted in said cage,said pump having means for returning surplus liquid from said barrelthrough said filter screen to assist in cleaning the same.

ciprocative in said barrel; and plunger driving.

means arranged in said compartment and comprising a rotatable shaft, aneccentric fast on said shaft, a ring surrounding said eccentric andoperative to lift said plunger, a frictionless bearing interposedbetween said ring and eccentric, and a spring which during reciprocationof said plunger holds it in contact with said ring, whereby said ringdoes not rotate with said eccentric. J.- 14. In a liquid pump having ahousing with a through bore therein and with an inlet port into saidbore; a hollow delivery plunger reciprocative in said bore and having atleast a portion of its peripheral rim longitudinally shaped for.cooperation with said inlet port; a delivery valve arranged at one endof said bore; a drive housing fastened to said plunger housing and opento the other end of said bore; plunger driving-means which is, arrangedwithin said drive housin'gand which comprises a rotatable drive shaft,an eccentric fastened on said shaft, a ring operative to lift saidplunger in its delivery stroke, and a frictionless bearing interposedbetween said ring and eccentric; a spring arranged at least in part inthe hollow plunger for moving said plunger in its suction stroke and forholding said plunger in contact with said ring; and delivery control andindicating mechanism which is mounted between said plunger and drivehousings and which is effective to turn said plunger in said barrel atany point of reciprocation of said plunger therein and to indicate theposition to which said plunger is turned.

BEN G. PARSONS.

